Linear alternating functionalized α-olefin/CO-copolymers and their use in preparing ion-selective membranes

ABSTRACT

Linear, alternating α-olefin-CO copolymers are obtainable by polymerization of a monomer mixture comprising 
     a) carbon monoxide, 
     b) 1-alkenes which are functionalized by a covalently bonded crown ether unit or cryptand unit A containing at least 5 heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur and/or selenium in the polyheteroatom framework, and, if desired, 
     c) C 2  -C 24  -1-alkenes.

The present invention relates to linear, alternating α-olefin-COcopolymers obtainable by polymerization of a monomer mixture comprising

a) carbon monoxide,

b) 1-alkenes which are functionalized by a covalently bonded crown etherunit or cryptand unit A containing at least heteroatoms selected fromthe group consisting of nitrogen, oxygen, sulfur and selenium in thepolyheteroatom framework, and, if desired,

c) C₂ -C₂₄ -1-alkenes.

The invention further relates to a process for preparing thefunctionalized α-olefin-CO copolymers and also to their use forproducing moldings, films, fibers and coatings. The invention alsorelates to ion-selective membranes which can be produced from thefunctionalized α-olefin-CO copolymers and their use as a constituent ofion-selective electrodes or chemically modified field effecttransistors.

Binary and ternary α-olefin-CO copolymers (carbon monoxide copolymers)have been adequately described in the specialized literature. Forexample, EP-B 121 965 discloses ethene-CO copolymers, EP-A 416 681discloses ethene-propene-CO copolymers. Carbon monoxide copolymers madeup of carbon monoxide and 1-butene or 1-hexene (cf. U.S. Pat. No.5,352,767) and also carbon monoxide terpolymers with longer-chainα-olefins have already been described (cf. unpublished German PatentApplication 19649072.3).

While conventional carbon monoxide-ethene copolymers are hard butbrittle and are now used as engineering plastics, carbon monoxidecopolymers having high mean molecular weights M_(w) (above 80,000 g/mol)(cf. the unpublished German Patent Application 196 10 358.4) or carbonmonoxide copolymers comprising long-chain α-olefin units (>C₆) also makeit possible to obtain molding compositions having a thermoplastic,elastomeric property profile, ie. copolymers whose glass transitiontemperatures (T_(g)) are less than 20° C.

The range of applications of the known carbon monoxide copolymers iskept within narrow limits by the selection of the monomer componentswhich form them.

It would therefore be desirable to be able to incorporate preciselythose monomer components which help to eliminate the disadvantages, eg.the brittleness, arising from the carbon monoxide framework and which atthe same time offer the opportunity of obtaining novel moldingcompositions which are also suitable for complex special applications byexploiting the properties given by just this basic framework, ie. havinghydrophobic behavior and nevertheless being relatively polar.

It is an object of the present invention to find novel carbon monoxidecopolymers which, as a result of selection of the monomer components,have a combination of matched properties in the product and aretherefore suitable for complex applications. In particular, it is anobject of the invention to provide ion-selective membranes which consistessentially of the carbon monoxide copolymers of the present inventionor have these as essential constituents and which do not have theindicated disadvantages of such membranes or membrane systems.

We have found that this object is achieved by means of the carbonmonoxide copolymers described in the introduction. Furthermore, we havefound a process for preparing the carbon monoxide copolymers of thepresent invention and their use for the production of fibers, moldings,coatings, films and ion-selective membranes. We have also foundion-selective membranes based on the carbon monoxide copolymers of thepresent invention and their use as constituents of ion-selectiveelectrodes or chemically modified field effect transistors.

Preference is given to α-olefin-CO copolymers which can be prepared bycopolymerization of the components

a) carbon monoxide,

b) a 1-alkene which is functionalized by a covalently bonded crown etherunit A containing from 5 to 10 oxygen atoms, and

c) a C₂ -C₂₄ -1-alkene.

Particular preference is given to α-olefin-CO copolymers which areobtainable by copolymerization of carbon monoxide (a)), a functionalized1-alkene (b)) of the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A                  (I)

where ##STR1## where ##STR2## where the substituents and indices havethe following meanings: Q=1,2-cyclohexyl or 1,2-phenyl,

k=independently of one another 2, 3 or 4,

p=1, 2, 3 or 4,

l=0 or 1,

r=1, 2, 3 or 4 and

q=an integer in the range from 4 to 24, in particular in the range from6 to 16,

and a C₃ -C₁₈ -1-alkene (c)).

The copolymers of the present invention are made up of units which arederived from the monomers carbon monoxide and one or more α-olefinicallyunsaturated compounds. In the binary copolymers of the presentinvention, the different monomer units are generally present in astrictly alternating order. In the ternary and higher copolymer systems,the order of carbon monoxide and olefin component is generally likewisestrictly alternating, with the crown ether-functionalized alkenemonomers being incorporated into the linear copolymer chain essentiallyrandomly in the possible olefin unit positions.

Suitable α-olefinically unsaturated compounds b) are in principle allmonomers of this class of compounds which are functionalized by acovalently bonded crown ether unit.

Examples of suitable α-olefinically unsaturated components are thepropenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl,1-nonenyl, 1-decenyl, 1-dodecenyl, 1-hexadecenyl, 1-octadecenyl or1-eicosenyl radicals. Preference is given to using compounds b) whoseα-olefinically unsaturated component is derived from C₅ -C₁₈ -1-alkenylradicals, particularly preferably C₇ -C₁₄ -1-alkenyl radicals.

For the purposes of the present invention, crown ethers in principleinclude not only crown ethers but also cryptands, podands and coronandsas are described, for example, in F. Vogtle, Supramolekulare Chemie, B.G. Teubner, Stuttgart, 1989. In the current context, a crown ether unitis, for example, a macrocyclic polyether compound which has a repeating--O--(CH₂)_(h) -unit (where h=2, 3 or 4). Such compounds include, forexample, the cyclic polyethers described in C. J. Pedersen, J. Am. Chem.Soc. 1967, 89, 7017-7036.

Cryptands include essentially all bicyclic polyheteroaromaticmacrocycles and in particular all macropolycyclic azapolyethers in whichtwo bridgehead nitrogen atoms are connected by bridges containing one ormore oxygen atoms. Suitable cryptands are, inter alia: [2.2.2]-,[2.2.1]-, [2.1.1]- and [1.1.1]-cryptand (for the nomenclature ofcryptands, see F. Vogtle, Supramolekulare Chemie, B. G. Teubner,Stuttgart, 1989, p. 47).

Preference is given to crown ether units A containing from 5 to 10oxygen atoms and cryptand units A containing from 3 to 6 oxygen atoms inwhich benzene and/or cyclohexane rings can also be integrated into themacrocycle framework, usually via linkages to adjacent ring carbons.

The units A are covalently bonded, generally via a single bond, to theolefinically unsaturated monomer. Bridging structural elements which canbe used are, for example, ether, ester, amide or carbamate groups or acarbon/carbon bond. A useful bonding unit is an ester group, where thecarboxylic acid radical forming this group preferably comes from thecomponent A and the hydroxyl group comes from the α-olefinicallyunsaturated monomer unit.

Accordingly, suitable compounds b) can be formally derived from alcoholssuch as allyl alcohol, but-3-en-1-ol, pent-4-en-1-ol, hex-5-en-1-ol,hept-6-en-1-ol, oct-7-en-1-ol, non-8-en-1-ol, dec-8-en-1-ol,dodec-11-en-1-ol, hexadec-15-en-1-ol, octadec-17-en-1-ol oreicos-19-en-1-ol and crown ethers or cryptands provided with carboxylicacid groups.

A crown ether having a covalently bonded carboxylic acid group isobtained, for example, by acylation of benzo-15-crown-5 (fornomenclature and synthesis see V. Percec, R. Rodenhouse, Macromolecules1989, 22, 4408) and subsequent oxidation by means of sodium hypobromite(cf. M. Bourgoin, K. H. Wong, J. Y. Hui, J. Smid, J. Am. Chem. Soc.1975, 97, 3462).

To link the carboxylic acid and alcohol components to form the compoundb), recourse can likewise be made to established methods (cf. Vogel'sHandbook of Practical Organic Chemistry, 5th Edition, Longman Scientific& Technical, 1989).

Preferred ester-bridged olefinically unsaturated compounds b) have, forexample, the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A                  (I)

where ##STR3## where ##STR4## where the substituents and indices havethe following meanings: Q=1,2-cyclohexyl or 1,2-phenyl,

k=independently of one another 2, 3 or 4,

p=1, 2, 3 or 4,

l=0 or 1,

r=1, 2, 3 or 4 and

q=an integer in the range from 4 to 24, in particular from 6 to 16.

Among the compounds mentioned above, particular preference is given tothose which have the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A

where q=8 or 9 and

the crown ether functionality is as follows: ##STR5## where

    G=--(CH.sub.2 CH.sub.2 O).sub.3 --(CH.sub.2 CH.sub.2)--.

An example of a suitable monomer compound b) for the preparation of thecopolymers of the present invention is accordingly 4'-(undec-10-enylcarboxylate)benzo-15-crown-5.

However, suitable compounds b) are not only uniform monomer charges, butalso mixtures of compounds in which it is immaterial whether thedifferences occur in the α-olefinically unsaturated monomer radical orin the crown ether or cryptand component or in both parts at the sametime.

The functionalized 1-alkenes b) described can be reacted with carbonmonoxide to give the linear, alternating copolymers of the presentinvention.

In addition, ternary and higher copolymer systems comprisingfunctionalized 1-alkenes b) are likewise obtainable.

In the case of ternary copolymers of the present invention, suitablefurther monomer components c) are in principle all α-olefinicallyunsaturated compounds of this class of compounds.

Suitable monomers c) for non-binary copolymers, in particular ternarycarbon monoxide copolymers, are, in particular, C₂ -C₂₄ -1-alkenes.

Examples which may be mentioned are ethene, propene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,1-dodecene, 1-hexadecene, 1-octadecene or 1-eicosene. Preference isgiven to using propene, 1-butene, 1-pentene, 1-hexene 1-heptene,1-octene, 1-nonene, 1-decene, 1-dodecene, 1-hexadecene and 1-octadecene,in particular propene, 1-hexene, 1-dodecene and 1-octadecene. Among thelast-named compounds, particular preference is given to using C₆ -C₁₂-1-alkenes.

Apart from the alkenes mentioned above, conjugated or isolated C₆ -C₂₀-dienes, for example 1,4-hexadiene and 1,5-hexadiene, are also suitableas olefinically unsaturated compounds c).

Preferred terpolymers are derived from carbon monoxide (a)), a compound(b)) which has the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A                  (I)

where ##STR6## where ##STR7## where the substituents and indices havethe following meanings: Q=1,2-cyclohexyl or 1,2-phenyl,

k=independently of one another 2, 3 or 4,

p=1, 2, 3 or 4,

l=0 or 1,

r=1, 2, 3 or 4 and

q=an integer in the range from 4 to 24, in particular from 6 to 16

and a C₃ -C₁₈ -1-alkene (c)).

In a particularly preferred embodiment, use is made of terpolymers whichcan be prepared from carbon monoxide, a compound of the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A                  (I),

where q=8 or 9

and ##STR8## where

    G=--(CH.sub.2 CH.sub.2 O).sub.3 --(CH.sub.2 CH.sub.2)--

and a C₆ -C₁₂ -alkene.

Among the ternary carbon monoxide copolymers, particular mention may bemade of the systems based on carbon monoxide/propene/4'-(undec-10-enylcarboxylate)benzo-15-crown-5, carbon monoxide/1-hexene/4'-(undec-10-enylcarboxylate)benzo-15-crown-5, carbonmonoxide/1-dodecene/4'-(undec-10-enyl carboxylate)benzo-15-crown-5 andcarbon monoxide/1-dodecadecene/4'-(undec-10-enylcarboxylate)benzo-15-crown-5, in particular carbonmonoxide/1-hexene/4'-(undec-10-enyl carboxylate)benzo-15-crown-5 andcarbon monoxide/1-dodecene/4'-(undec-10-enylcarboxylate)benzo-15-crown-5.

The mean molecular weight M_(w) (measured by gel permeationchromatography (GPC) at 25° C. using Microstyragel (Waters) as columnmaterial and chloroform as solvent against a polystyrene standard) ofthe carbon monoxide copolymers of the present invention are usually inthe range from 5000 to 200,000 g/mol, but copolymers having meanmolecular weights up to 300,000 g/mol and even 400,000 g/mol can also beobtained.

While mean molecular weights M_(w) of greater than 100,000 g/mol cangenerally be obtained without difficulty when using relativelyshort-chain monomer components c), eg. propene, the results achieved inthe presence of long-chain alkenes such as 1-octadecene are usuallylower.

The terpolymers of the present invention are notable for, inter alia,their thermoplastic, elastomeric properties and accordingly have T_(g)values in the range from 20 to -90° C. For example, carbon monoxidecopolymers having a particularly useful thermoplastic, elastomericproperty profile are those terpolymers whose component b) is derivedfrom an α-olefin functionalized by benzo-15-crown-5 and whose componentc) is derived from a C₆ -C₁₂ -alkene.

Terpolymers according to the present invention also include thosecompounds in which the molar proportion of the component b) in theoverall copolymer is 0.01 mol %. However, molar proportions of 5 or 10%or even above can generally be obtained without difficulty.

The proportion of head-to-tail linked units in the terpolymers of thepresent invention is generally in the range from 1 to 80% and for carbonmonoxide copolymers containing, for example, a benzo-15-crown-5 functionand C₃ -C₁₂ -1-alkenes is usually in the range from 40 to 70%.

The molecular weight distribution M_(w) /M_(n) (weight average/numberaverage) of the copolymers of the present invention, measured by gelpermeation chromatography (GPC) using a method similar to that describedabove, is generally from 1.2 to 4, but is preferably less than 2.5.

The molar ratio of carbon monoxide to the sum of the structural unitsderived from the olefinically unsaturated monomers in the binary andhigher carbon monoxide copolymers of the present invention is generally1:1.

The polymer materials of the present invention have, owing to theirimpact-modified properties and their biocompatible behavior, manypossible uses, eg. in the field of polymer blend technology or inmedical technology.

To prepare the linear, thermoplastic, elastomeric copolymers of thepresent invention, carbon monoxide can be copolymerized witholefinically unsaturated compounds in a virtually alcohol-free orwater-free polymerization medium in the presence of a catalyst whoseactive composition is formed from

A') a metal complex of the formula (II) ##STR9## where the bold arrowsrepresent a coordinate bond and the substituents and indices have thefollowing meanings:

M is a metal from group VIIIB of the Periodic Table of the Elements

E¹, E² are each an element from group VA of the Periodic Table of theElements,

Z is a bridging structural unit comprising one, two, three or foursubstructural units of elements of groups IVA, VA and VIA of thePeriodic Table of the Elements,

R¹ to R⁴ are substituents selected from the group consisting of C₁ -C₂₀-organic and C₃ -C₃₀ -organosilicon radicals, where the radicals maycontain one or more elements of groups IVA, VA, VIA and VIIA of thePeriodic Table of the Elements,

L¹, L² are formally uncharged Lewis base ligands,

X are monovalent or divalent anions,

m, n are 1 or 2,

where m×n=2, and

B') is an activator component which contains a hydroxyl group in themolecule and is used, based on M in (II), in an amount of from 0 to 1500molar equivalents.

As a further process for preparing the linear, thermoplastic,elastomeric copolymers of the present invention, it is possible tocopolymerize carbon monoxide with olefinically unsaturated compounds ina virtually alcohol-free or water-free polymerization medium in thepresence of a catalyst whose active composition is formed from

i) a salt of a metal M of group VIIIB of the Periodic Table of theElements,

ii) one or more compounds selected from the group consisting of proticacids and Lewis acids,

iii) a chelating compound of the formula (III)

    R.sup.1 R.sup.2 E.sup.1 --Z--E.sup.2 R.sup.3 R.sup.4       (III),

where the substituents and indices have the following meanings:

E¹, E² are each an element from group VA of the Periodic Table of theElements,

Z is a bridging structural unit comprising one, two, three or foursubstructural units of elements of groups IVA, VA and VIA of thePeriodic Table of the Elements,

R¹ to R⁴ are substituents selected from the group consisting of C₁ -C₂₀-organic and C₃ -C₃₀ -organosilicon radicals, where the radicals maycontain one or more elements from groups IVA, VA, VIA and VIIA of thePeriodic Table of the Elements,

d) an activator component B') which contains a hydroxyl group in themolecule and is used, based on M in (II), in an amount of from 0 to 1500molar equivalents.

The polymerizations for preparing the carbon monoxide copolymers of thepresent invention can be carried out either batchwise or continuously inthe presence of a polymerization catalyst comprising A'), or i), ii),iii) and possibly B') or iv).

Suitable polymerization catalysts are transition metal compounds ofgroup VIIIB of the Periodic Table of the Elements which are in the formof defined metal complexes (II) or can be formed in situ from a metalsalt i) of a metal of group VIIIB of the Periodic Table of the Elements,protic and/or Lewis acids ii) and a chelating compound iii) of theformula (III). If desired, activators B') or iv) can be added to themetal compounds.

Suitable metals M are the metals of group VIIIB of the Periodic Table ofthe Elements, ie. iron, cobalt and nickel and especially the platinummetals ruthenium, rhodium, osmium, iridium, platinum and veryparticularly palladium. In the metal complexes, the metals nickel,palladium and platinum generally formally bear two positive charges, themetals cobalt, rhodium and iridium generally formally bear one positivecharge and the metals iron, ruthenium and osmium are generally formallyuncharged.

Suitable elements E¹ and E² in the chelating ligand, hereinafter alsoreferred to as chelating compound (III), are the elements of main groupV of the Periodic Table of the Elements (group VA), ie. nitrogen,phosphorus, arsenic, antimony or bismuth. Particularly suitable elementsare nitrogen and phosphorus, in particular phosphorus. The chelatingligand or the chelating compound (III) can contain different elements E¹and E², for example nitrogen and phosphorus, but it preferably containsidentical elements E¹ and E² and in particular E¹ and E² are phosphorus.

The bridging structural unit Z is a group of atoms which connects thetwo elements E¹ and E² to one another. Substructural units comprisingone atom or a plurality of atoms connected to one another from groupIVA, VA or VIA of the Periodic Table of the Elements usually form thebridge between E¹ and E². Possible free valences of these bridge atomscan be satisfied in various ways, for example by bonding to hydrogen orelements of group IVA, VA, VIA or VIIA of the Periodic Table of theElements. These substituents can form ring structures with one anotheror with the bridge atom.

Well suited bridging structural units Z are those comprising one, two,three or four elements from group IVA of the Periodic Table of theElements, for example methylene (--CH₂ --), 1,2-ethylene (--CH₂ --CH₂--), 1,3-propylene (--CH₂ --CH₂ --CH₂ --), 1,4-butylene,1,3-disilapropylene (--R⁵ R⁶ Si--CH₂ --SiR⁵ R⁶ --, where R⁵, R⁶ are C₁-C₁₀ -alkyl, C₆ -C₁₀ -aryl), ethylidene (CH₃ (H)C═), 2-propylidene((CH₃)₂ C═), diphenylmethylene ((C₆ H₅)₂ C═) or ortho-phenylene.

Particularly suitable bridging structural units are 1,2-ethylene,1,3-propylene and 1,4-butylene.

Suitable organic radicals R¹ to R⁴ are, independently of one another,aliphatic, cycloaliphatic and aromatic radicals having from 1 to 20carbon atoms, for example the methyl, ethyl, 1-propyl, 1-butyl,1-pentyl, 1-hexyl and 1-octyl groups as well as their structuralanalogues. Linear arylalkyl groups having from 1 to 10 carbon atoms inthe alkyl radical and from 6 to 20 carbon atoms in the aryl radical, forexample benzyl, are also suitable. Further radicals R¹ to R⁴ which maybe mentioned are aryl radicals such as tolyl, anisyl, preferablyortho-anisyl, xylyl and other substituted phenyl groups, in particularphenyl.

Possible cycloaliphatic radicals are C₃ -C₁₀ -monocyclic systems such ascyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl, particularlypreferably cyclohexyl.

Suitable branched aliphatic radicals are C₃ -C₂₀ --, preferably C₃ -C₁₂-alkyl radicals such as i-propyl, i-butyl, s-butyl, neopentyl andt-butyl.

Particularly suitable branched aliphatic radicals are t-butyl, i-propyland s-butyl.

Alkyl groups having branching located further out are also well suitedas substituents R¹ to R⁴, for example i-butyl, 3-methylbut-2-yl and4-methylpentyl.

The substituents R¹ to R⁴ can also, independently of one another,contain atoms from group IVA, VA, VIA or VIIA of the Periodic Table ofthe Elements, for example halogen, oxygen, sulfur, nitrogen or silicon,for example the bis(trimethylsilyl)methyl group. Functional groups whichare inert under the polymerization conditions are also possibilities inthis context.

Preferred heterosubstituents R¹ to R⁴ are C₃ -C₃₀ -organosiliconradicals, ie. tetravalent silicon atoms which are bonded to E¹ or E² andwhose remaining valences bear three organic radicals such as alkyland/or aryl radicals, where the total number of carbon atoms in thesethree radicals bonded to silicon is in the range from three to thirty.Examples which may be mentioned are the trimethylsilyl,t-butyldimethylsilyl and triphenylsilyl groups, in particular thetrimethylsilyl group.

The chelating ligand or chelating compound (III) used is preferably1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane or1,4-bis(diphenylphosphino)butane.

Very particularly preferred compounds as chelating ligand or chelatingcompound (III) are 1,3-bis(diphenylphosphino)propane and1,4-bis(diphenylphosphino)butane.

Suitable formally uncharged ligands L¹, L² are Lewis bases in general,ie. compounds, preferably organic compounds, having at least one freeelectron pair or water.

Well suited ligands are Lewis bases whose free electron pair or pairsis/are located on a nitrogen or oxygen atom, ie. nitriles, R--CN,ketones, ethers or preferably water.

Suitable Lewis bases which may be mentioned are C₁ -C₁₀ -nitriles suchas acetonitrile, propionitrile or benzonitrile, or C₃ -C₁₀ -ketones suchas acetone or acetylacetone or else C₂ -C₁₀ -ethers such as dimethylether, diethyl ether or tetrahydrofuran.

Ligands L¹, L² in (II) which are particularly suitable for catalystswhich need no activator B') or iv) are those of the formula (IV)

    T--OH                                                      (IV)

where T is hydrogen or a C₁ -C₁₅ -organic radical bearing a Lewis basegroup. Well suited C₁ -C₁₅ -organic radicals T are, for example, linearor cyclic .paren open-st.CH₂ .paren close-st._(n) units, where n is from1 to 10, ie. methylene, 1,2-ethylene, 1,3-propylene, 1,4-butylene,1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonyleneor 1,10-decylene.

Suitable Lewis base groups are ether, ester, ketone, amine, phosphineand in particular nitrile (--C.tbd.N) or tertiary amine.

Examples of well suited compounds T--OH are water andα,ω-hydroxynitriles such as NC .paren open-st.CH₂ .paren close-st._(n)OH where n=1-10 and (2-hydroxymethyl)tetrahydrofuran, as well as(2-hydroxymethyl)(N-organo)pyrrolidines (IVa) and(2-hydroxymethyl)(N-organo)piperidines (IVb) ##STR10## where R' is C₁-C₁₀ -alkyl or C₃ -C₁₀ -cycloalkyl, for example methyl, ethyl, n-propyl,i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, cyclopentyl andcyclohexyl. R' can also be C₆ -C₁₀ -aryl, for example phenyl ornaphthyl.

In general, the ligands T--OH are, with the exception of water, bondedto the metal M in (II) via the above-defined Lewis base group.

The choice of the anions X is generally not critical. Examples ofsuitable anions X in (II) are perchlorate, sulfate, phosphate, nitrateand carboxylates such as acetate, trifluoroacetate, trichloroacetate,propionate, oxalate, citrate and benzoate, and also conjugated anions oforganosulfonic acids, for example methylsulfonate,trifluoromethylsulfonate and p-toluenesulfonate, also tetrafluoroborate,tetraphenylborate, tetrakis(pentafluorophenyl)borate,hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate.Preference is given to using perchlorate, trifluoroacetate, sulfonatessuch as methylsulfonate, trifluoromethylsulfonate andp-toluenesulfonate, tetrafluoroborate or hexafluorophosphate and inparticular trifluoroacetate, perchlorate or p-toluenesulfonate as anionX.

Particularly well suited metal complexes (II) which may be mentioned are(1,3-bis(diphenylphosphino)propane)bis(acetonitrile)palladiumbis(tetrafluoroborate) (=[Pd(dppp)(NCCH₃)₂ ](BF₄)₂,dppp=1,3-bis(diphenylphosphino)propane),(1,3-bis(diphenylphosphino)propane)diaquopalladiumbis(tetrafluoroborate),(1,3-bis(diphenylphosphino)propane)bis(3-hydroxypropionitrile)palladiumbis(tetrafluoroborate),(1,4-bis(diphenylphosphino)butane)bis(acetonitrile)palladiumbis(tetrafluoroborate) and(1,4-bis(diphenylphosphino)butane)diaquopalladiumbis(tetrafluoroborate).

The metal complexes of the formula (II) are generally prepared byliterature methods, as described in Makromol. Chem. 1993, 194, p. 2579.Tetrakis(ligand)metal complexes such as tetrakis(acetonitrile)palladiumbis(tetrafluoroborate) can usually be reacted with the chelatingcompounds (III) and the ligands L¹, L² or TOH to give the metalcomplexes (II). A preferred method of preparing aquo complexes (II) isreacting the (chelating phosphine)(acetonitrile)metal complexes withwater. The reaction is generally carried out in a solvent, for exampledichloromethane, acetonitrile or water, at from -78 to 40° C.

In the in situ generation of the polymerization catalysts, the metals Mare usually used in divalent form as their salts and are brought intocontact with the chelating compound iii) of the formula (III) and theacids ii). This can occur before contacting the catalytically activecomposition obtainable in this way with the monomers and, if desired, afurther activator iv), generally outside the polymerization reactor.However, the reaction of the individual components metal salt i),chelating compound iii) of the formula (III), acid ii) and any activatorcomponent iv) used can also be carried out in the polymerizationreactor, in the presence of the monomers.

Suitable salts of usually divalent metals M are halides, sulfates,phosphates, nitrates and carboxylates such as acetates, propionates,oxalates, citrates and benzoates, and also sulfonic acid salts such asmethylsulfonates, trifluoromethylsulfonates and p-toluenesulfonates.Preference is given to using carboxylates, sulfonic acid derivatives andin particular acetates.

Particularly suitable catalyst components i) are palladiumdicarboxylates, preferably palladium diacetate, palladium dipropionate,palladium bis(trifluoroacetate) and palladium oxalate, and alsopalladium sulfonates, preferably palladiumbis(trifluoromethanesulfonate), palladium bis(methanesulfonate) andpalladium bis(p-toluenesulfonate). Particular preference is given tousing palladium diacetate.

As catalysts constituents ii), it is possible to use Lewis and proticacids and mixtures thereof.

Suitable protic acids ii) are strong mineral acids such as sulfuric acidand perchloric acid, and also strong organic acids such astrichloroacetic and trifluoroacetic acids, and also the sulfonic acidsmethanesulfonic acid, p-toluenesulfonic acid and benzenesulfonic acid,ie. in each case acids which preferably have a pK_(a) of less than 3.

The acidic salts of strong acids and weak bases, for example ammoniumsalts of the abovementioned acids, are also suitable.

Examples of suitable Lewis acids are halides of the elements of groupIIIA of the Periodic Table of the Elements, for example borontrifluoride, boron trichloride, aluminum trifluoride and aluminumtrichloride, halides of the elements of group VA of the Periodic Tableof the Elements, eg. phosphorus pentafluoride and antimonypentafluoride, and also halides of the metals of transition group IVB ofthe Periodic Table of the Elements, for example titanium tetrachlorideand zirconium tetrachloride. Further suitable Lewis acids areorganically substituted Lewis acids, for exampletris(pentafluorophenyl)borane.

As Lewis acids, preference is given to using boron trifluoride, antimonypentafluoride or tris(pentafluorophenyl)borane.

Particularly preferred components ii) are those which possess a weaklycoordinating conjugated anion, ie. an anion which forms only a weak bondto the central metal of the complex, for example tetrafluoroborate,hexafluorophosphate, perchlorate, trifluoroacetate,trifluoromethylsulfonate, p-tosylate and borates such ascatecholatoborate and tetraarylborate, where particularly suitable arylgroups are 2,5-dimethylphenyl, 2,5-bis(trifluoromethyl)phenyl andpentafluorophenyl.

Otherwise, suitable catalyst components i) and ii) are those which aregenerally known from EP-A 501 576 and 516 238 for systems containingbisphosphines.

As component c), the catalyst systems comprise a chelating compound R¹R² E¹ --Z--E² R³ R⁴ (III), which has already been described in thediscussion of the metal complexes (II).

The ratio of the catalyst constituents i), ii) and iii) to one anotheris generally selected such that the molar ratio of the metal compound i)to the acid ii) is from 0.01:1 to 100:1, preferably from 0.1:1 to 1:1,and the molar ratio of the metal compound i) to the component iii) isfrom 0.01:1 to 10:1, preferably from 0.1:1 to 2:1.

The activator component B') or iv) is generally a chemical compoundwhich contains at least one hydroxyl group in the molecule. Theseinclude, in particular, C₁ -C₁₀ -alcohols such as methanol, ethanol,n-propanol, i-propanol, n-butanol, i-butanol, s-butanol, t-butanol,n-hexanol, n-octanol, n-decanol and cyclohexanol, phenol or water.Preference is given to using methanol and/or water as activatorcomponent B') or iv).

The molar ratio of activator component B') or iv) to metal M is in therange from 0 to 1500, preferably in the range from 0 to 1300. It hasfound to be advantageous not to exceed the maximum ratio in thepolymerization reaction, since otherwise the mean molecular weightsM_(w) of the carbon monoxide copolymers formed can be too low.

The addition of the activator B') or iv) becomes superfluous only whenthe Lewis base ligands L¹, L² present in the catalyst are ones whichcontain a hydroxyl group in the molecule and have been defined moreprecisely above by the formula T--OH (IV).

Particularly suitable reaction parameters for preparing the linear,thermoplastic, elastomeric copolymers of carbon monoxide andolefinically unsaturated compounds have been found to be pressures offrom 100 to 500,000 kPa, preferably from 500 to 350,000 kPa and inparticular from 1000 to 10,000 kPa, and temperatures of from -50 to 400°C., preferably from 10 to 250° C. and in particular from 20 to 100° C.

The polymerization reactions can be carried out in the gas phase in afluidized bed or stirred, in suspension, in liquid or supercriticalmonomers and in solvents which are inert under the polymerizationconditions.

The polymerization reactions can be carried out in a virtuallyalcohol-free or water-free polymerization medium. This means that noalcohol or water apart from perhaps the activator component B') or iv)is added to the reaction mixture comprising monomers, catalyst and, ifdesired, inert solvent or suspension medium.

Suitable inert solvents and suspension media are those which contain nohydroxyl group in the molecule, ie. ethers such as diethyl ether,tetrahydrofuran, aromatic solvent such as benzene, toluene,ethylbenzene, chlorobenzene, aliphatic hydrocarbons such as i-butane orchlorinated aliphatic hydrocarbons such as dichloromethane,1,1,1-trichloromethane or mixtures of these.

A polymerization method which has been found to be particularly wellsuited is to place the catalyst in an inert solvent, if desiredsubsequently add the activator component B') or iv) and subsequently addthe monomers and to carry out the polymerization at from 20 to 100° C.and a pressure in the range from 1000 to 10,000 kPa.

The carbon monoxide copolymers of the present invention can be processedby means of injection molding, blow molding, spinning, rotation molding,extrusion or spin coating. It is also possible to coat metallic, ceramicand other surfaces, eg. those of polymer materials.

The carbon monoxide copolymers of the present invention are suitable forproducing fibers, films, moldings and coatings. Furthermore, they aresuitable for producing ion-selective membranes.

As a result of the above-described controlled incorporation of crownether functions into the carbon monoxide copolymer framework and thepossibility of influencing the thermoplastic, elastomeric behavior ofthese copolymers by means of the molecular weight and/or theincorporation of long-chain olefin building blocks, it is possible toproduce films which are particularly suitable as ion-selectivemembranes. These membranes can be used, inter alia, as a constitutent ofcompact analytical devices such as ion-selective electrodes (cf. J.Moody, B. B. Saad, J. D. R. Thomas, Selective Electrode Rev. 1988, 10,71) or in chemically modified field effect transistors (CHEMFETs forshort) (see also D. N. Reinhoudt, J. F. J. Engbersen, Z. Brzozka, H. N.van den Vlekkert, G. W. N. Honig, H. A. J. Holterman, U. H. Verkerk,Anal. Chem. 1994, 66, 3618). The membranes of the present invention areparticularly notable for not requiring any plasticizer and for theactivation energy for the transport of ions being minimized as a resultof the presence of polar CO groups in the polymer. At the same time,however, the hydrophobic surface character is retained, whichsubstantially suppresses or completely eliminates the process of foulingin the aqueous phase.

Accordingly, membranes based on the carbon monoxide copolymers of thepresent invention open out a simple route to, for example, sensorcomponents which have a long life and can be produced on a large scalewithout difficulty.

The invention is illustrated by the following examples.

EXAMPLES

I. Measurement methods and apparatus

The molecular weights M_(w) and the molecular weight distributions M_(w)/M_(n) were determined by GPC in CHCl₃ using a Waters 590 HPLC pump,Waters Microstyragel columns having pore sizes of 10⁵, 10⁴ and 10³ Å, aWaters 410 differential refractometer and a Waters 486 UV detector.

¹ H-NMR and ¹³ C-NMR measurements were carried out using a Bruker AC 200spectrometer.

The DSC data were determined using a Perkin Elmer DSC 7 instrumentequipped with a Perkin Elmer TAC 7/DX thermocontroller; cyclohexane,indium and gallium were used for calibration.

Melting points were determined on a Mettler FP82HT hotplate and aMettler FP90 processor using a Zeiss Axioskop Pol microscope.

IR spectra were recorded on a Bruker IFS 66V spectrometer. The samplesfor measurement were produced by applying a thin film to KBr plates froma dichloromethane solution.

The catalyst used was [Pd(dppp)(NCCH₃)₂ ] (BF₄)₂, prepared from[Pd(NCCH₃)₄ ](BF₄)₂ (Aldrich) and 1,3-bis(diphenylphosphino)propane(=dppp) (Strem Chemicals) as described by F. Y. Xu, A. X. Zhao, J. C. W.Chien, Makromol. Chem. 1993, 194, 2597.

Toluene, dichloromethane and triethylamine were distilled over sodium,benzophenone and calcium hydride or KOH respectively before use.Methanol was purified by distillation over magnesium wire.

II. Preparation of 4'-(undec-10-enylcarboxylate)benzo-15-crown-5 (V)(component b))

A mixture of 4'-benzo-15-crown-5-carboxylic acid (10 g, 32 mmol),obtainable from benzo-15-crown-5 by the method of M. Bourgoin, K. H.Wong, J. Y. Hui, J. Smid, J. Am. Chem. Soc. 1975, 97, 3462, and thionylchloride (50 ml, 293 mmol) was refluxed for 6 hours, excess thionylchloride was distilled off and the residue was dissolved indichloromethane (40 ml). Undec-10-en-1-ol (6.54 g, 38.4 mmol), dissolvedin dichloromethane (20 ml), was admixed with triethylamine (6.8 ml, 48mmol) in dichloromethane (20 ml) and the mixture was added dropwise atroom temperature to the reaction mixture. After 12 hours under reflux,the reaction was stopped by cooling and washing three times with water.

The organic phase was separated off, dried over MgSO₄, the organicsolvent was removed and the resulting crude product was chromatographedon silica gel using first dichloromethane and subsequently a 95/5 (v/v)mixture of dichloromethane and methanol (yield: 11.5 g), m.p.: 42-43° C.

IR (KBr) 1712 cm⁻¹ (C═O). ¹ H NMR (CDCl₃): δ=1.25 (m, --(CH₂)₆ --, 12H),1.70 (m, --CH₂ CH₂ O₂ C--, 2H), 2.0 (m, CH₂ ═CHCH₂ --, 2H) 3.70 (s,--OCH₂ CH₂ OCH₂ CH₂ O--, 8H), 3.85 (d, ArOCH₂ CH₂ O--, 4H), 4.10 (d,ArOCH₂ CH₂ O--, 4H), 4.20 (t, --CH₂ O₂ CAr, 2H), 4.85 (m, CH═CH₂ --,2H), 5.70 (m, CH═CH₂ --, 1H), 6.80 (d, ArH, 1H), 7.45 (s, ArH, 1H), 7.60(d, ArH, 1H). ¹³ C NMR (CDCl₃): δ=25.84, 28.57, 28.71, 28.89, 29.20 and29.26 (--(CH₂)₇ --), 33.59 (CH₂ ═CHCH₂ --), 64.73 (--CH₂ O₂ CAr), 68.46,68.89, 69.10, 69.24, 70.15, 70.25 and 70.99 (crown ether carbons),111.92, 114.49, 123.05, 123.66, 148.29 and 152.95 (aromat. C), 113.96(CH₂ ═CH--), 138,93 (CH═CH₂ --), 166.15 (C═O).

III. Terpolymerization of 4'-(undec-10-enyl carboxylate)benzo-15-crown-5(V) and carbon monoxide with propene (C3), 1-hexene (C6), 1-dodecene(C12) and 1-octadecene (C18)

General Procedure:

The polymerizations were carried in 25 ml of dichloromethane in 50 or100 ml steel autoclaves by stirring at room temperature under a COpressure of 6.1×10⁶ Pa. The amount of the activator (methanol) added ineach case, the amounts of α-olefin and catalyst used and the reactionconditions are shown in Table 1.

The polymerization was stopped by venting the autoclave and adding of anexcess of methanol. Subsequently, the solvent was removed, the residuewas taken up in dichloromethane and freed of catalyst residues by meansof a short silica gel column. The last traces of unreacted4'-(undec-10-enylcarboxylate)benzo-15-crown-5 and α-olefin (for C3, C6,C12) were removed by (repeated) precipitation of the products in adichloromethane solution by addition of methanol. Removal of the solventunder reduced pressure gave the desired terpolymer. Unreacted1-octadecene was removed by chromatography on silica gel (0.063-0.100mm) using dichloromethane and a 90/10 (v/v) mixture of dichloromethaneand methanol. The product properties of C3, C6, C12, C18 are shown insection IV. and also Table 2.

IV. Spectroscopic data

C3: ¹ H NMR (CDCl₃): δ=1.05 (broad, --CH₃, 3H), 2.20-2.50 (broad,--CH--, 1H), 2.70-3.20 (broad, --CH₂ --, 2H), 3.70 (s, --OCH₂ CH₂ OCH₂CH₂ O--, 8H), 3.85 (d, ArOCH₂ CH₂ O--, 4H), 4.10 (d, ArOCH₂ CH₂ O--,4H), 4.20 (t, --CH₂ O₂ CAr, 2H), 6.80 (d, ArH, 1H), 7.45 (s, ArH, 1H),7.60 (d, ArH, 1H). ¹³ C NMR (CDCl₃): δ=16.20 (--CH₃), 39.86 (--CH₂ --framework), 44.46 (--CH-- framework), 207.5 (C═O framework, tail--taillinkage), 212.0 (C═O framework, head-tail linkage), 215.6 (C═Oframework, head--head linkage).

C6: ¹ H NMR (CDCl₃): δ=0.85 (t, --CH₃, 3H), 1.00-1.80 (broad, --(CH₂)₃--, 6H), 2.20-2.60 (broad, --CH--, 1H), 2.70-3.20 (broad, --CH₂ --, 2H),3.70 (s, --OCH₂ CH₂ OCH₂ CH₂ O--, 8H), 3.85 (d, ArOCH₂ CH₂ O--, 4H),4.10 (d, ArOCH₂ CH₂ O--, 4H), 4.20 (t, --CH₂ O₂ CAr, 2H), 6.80 (d, ArH,1H), 7.45 (s, ArH, 1H), 7.60 (d, ArH, 1H). ¹³ C NMR (CDCl₃): δ=13.50(--CH₃), 22.30 (--CH₂ CH₃), 23.19, 25.61, 26.38, 28.84, 30.54 and 32.29(--(CH₂)_(n) --, 41-42 (--CH-- framework), 43-45 (--CH₂ -- framework),68.20, 68.64, 68.86, 69.00, 69.91, 70.00 and 70.74 (crown ethercarbons), 111.65, 114.18, 122.74, 123.44, 148.06 and 152.73 (aromat. C),165.83 (C═O ester), 208-211 (C═O framework, tail--tail linkage), 212-214(C═O framework, head-tail linkage), 214-216 (C═O framework, head--headlinkage).

C12: ¹ H NMR (CDCl₃): δ=0.85 (t, --CH₃, 3H), 1.0-1.80 (broad, --(CH₂)₉--, 18H), 2.20-2.70 (broad, --CH--, 1H), 2.70-3.20 (broad, --CH₂ --,2H), 3.70 (s, --OCH₂ CH₂ OCH₂ CH₂ O--, 8H), 3.85 (d, ArOCH₂ CH₂ O--,4H), 4.10 (d, ArOCH₂ CH₂ O--, 4H), 4.20 (t, --CH₂ O₂ CAr, 2H), 6.80 (d,ArH, 1H), 7.45 (s, ArH, 1H), 7.60 (d, ArH, 1H). ¹³ C NMR (CDCl₃):δ=13.70 (--CH₃), 22.30 (--CH₂ CH₃), 23.27, 26.60, 28.98, 29.23, 30.91and 31.54 (--(CH₂)_(n) --, 41-42 (--CH-- framework), 43-45 (--CH₂ --framework), 68.17, 68.58, 68.86, 69.91 and 70.74 (crown ether carbons),111.52, 114.14, 122.73, 123.37, 148.05 and 152.70 (aromat. C), 165.60(C═O ester), 207-209 (C═O framework, tail--tail linkage), 210-212 (C═Oframework, head-tail linkage), 212-215 (C═O framework, head--headlinkage).

C18: ¹ H NMR (CDCl₃) δ=0.85 (t, --CH₃, 3H), 1.0-1.80 (broad, --(CH₂)₁₅--, 30 H), 2.20-2.70 (broad, --CH--, 1H), 2.70-3.20 (broad, --CH₂ --,2H), 3.70 (s, --OCH₂ CH₂ OCH₂ CH₂ O--, 8H), 3.85 (d, ArOCH₂ CH₂ O--,4H), 4.10 (d, ArOCH₂ CH₂ O--, 4H), 4.20 (t, --CH₂ O₂ CAr, 2H), 6.80 (d,ArH, 1H), 7.45 (s, ArH, 1H), 7.60 (d, ArH, 1H). ¹³ C NMR (CDCl₃):δ=13.76 (--CH₃), 22.36 (--CH₂ CH₃), 23.42, 24.30, 25.71, 26.68, 28.44,29.08, 29.41, 31.03 and 31.62 (--(CH₂)_(n) --, 41-42 (--CH-- framework),43-45 (--CH₂ -- framework), 68.10, 68.52, 68.84, 69.83 and 70.60 (crownether carbons), 111.57, 114.14, 122.86, 123.47, 147.95 and 152.56(aromat. C), 165.60 (C═O ester), 207-209 (C═O framework, tail--taillinkage), 210-212 (C═O framework, head-tail linkage), 212-215 (C═Oframework, head--head linkage).

                                      TABLE 1                                     __________________________________________________________________________    Polymerization conditions                                                          α-Olefin,                                                                     V              t.sub.pol.sup.b),                                                                 CO.sub.consump.sup.c),                                                               Yield.sup.d),                            Polymer                                                                            g (mmol)                                                                            g (mmol)                                                                            Methanol/Pd.sup.a)                                                                     h   Pax10.sup.-5                                                                         g                                        __________________________________________________________________________    C3   25                                                                              (594)                                                                             0.3                                                                             (0.7)                                                                             1100     40  25.sup.e)                                                                            2.5                                        C6 1.3 (15.9) 0.6 (1.4) 1100 45 20.sup.f) 0.7                                 C12 3.8 (22.6) 0.5 (1.1) 300 64 20.sup.f) 1.2                                 C18 4.7 (18.8) 0.6 (1.2) 300 43 18.sup.f) 0.5                               __________________________________________________________________________     .sup.a) Molar ratio of activator (methanol) to palladium                      .sup.b) Polymerization time.                                                  .sup.c) Carbon monoxide consumption. The initial pressure was 6 ×       10.sup.6 Pa in all cases.                                                     .sup.d) Yield of product isolated after precipitation and chromatography.     .sup.e) 100 ml autoclave.                                                     .sup.f) 50 ml autoclave.                                                 

                                      TABLE 2                                     __________________________________________________________________________    Terpolymer properties                                                             M.sub.w.sup.a)                                                                         (V) (mol %).sup.b)                                                                      H-T.sup.c)                                                                         ν.sub.C═O.sup.d)                                                            T.sub.g.sup.e)                                                                    T.sub.m.sup.e)                           Polymer                                                                           g/mol                                                                             M.sub.w /M.sub.n.sup.a)                                                            .sup.1 H NMR                                                                       .sup.13 C NMR                                                                      mol %                                                                              cm.sup.-1                                                                          ° C.                                                                       ° C.                              __________________________________________________________________________    C3  131200                                                                            1.8  ˜0.2                                                                         --.sup.h)                                                                          57   1706  19 108                                        C6  12800 1.5 5.4 4.7 60 1708 -18 --.sup.g)                                   C12  11000 2.0 4.4 4.3 52 1708 -76 --.sup.g)                                  C18  5300 1.8 9.6 9.0 4.9 1710 --.sup.f) 17                                 __________________________________________________________________________     .sup.a) M.sub.w (M.sub.w /M.sub.n) determined by means of GPC in              chloroform (against a polystyrene standard).                                  .sup.b) (V): Determined by means of the proportion of benzo15-crown-5         units (mol %).                                                                .sup.c) Headtail units: Regioregularity determined by means of the            headtail sequences using .sup.13 C NMR.                                       .sup.d) C═O Infrared absorption bands.                                    .sup.e) Determined from the second run (10K/min) using the tangent method     (DSC).                                                                        .sup.f) T.sub.g not able to be determined.                                    .sup.g) T.sub.m not able to be determined.                                    .sup.h) No signal detectable by means of .sup.13 C NMR.                  

We claim:
 1. A linear, alternating α-olefin-CO copolymer obtained bypolymerization of a monomer mixture comprisinga) carbon monoxide, b)1-alkenes which are functionalized by a covalently bonded crown etherunit or cryptand unit A containing at least 5 heteroatoms selected fromthe group consisting of nitrogen, oxygen, sulfur and selenium in thepolyheteroatom framework, and, if desired, c) C₂ -C₂₄ -1-alkenes.
 2. Alinear, alternating α-olefin-CO copolymer as claimed in claim 1,whereina) is carbon monoxide, b) is a 1-alkene which is functionalizedby a covalently bonded crown ether unit A containing from 5 to 10 oxygenatoms, and c) is a C₂ -C₂₀ -1-alkene.
 3. A linear, alternatingα-olefin-CO copolymer as claimed in claim 1, whereina) is carbonmonoxide, b) is a compound of the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A                  (I)

where ##STR11## where ##STR12## where the substituents and indices havethe following meanings: Q=1,2-cyclohexyl or 1,2-phenyl, k=independentlyof one another 2, 3 or 4, p=1, 2, 3 or 4, l=0 or 1, r=1, 2, 3 or 4 andq=an integer in the range from 4 to 24 and c) is a C₃ -C₁₈ -1-alkene. 4.A linear, alternating α-olefin-CO-copolymer as claimed in claim 1,whereina) is carbon monoxide, b) is a compound of the formula (I)

    CH.sub.2 ═CH(CH.sub.2).sub.q O(O)C--A                  (I)

where q=8 or 9 and ##STR13## where G=--(CH₂ CH₂ O)₃ --(CH₂ CH₂)-- and c)is a C₆ -C₁₂ -1-alkene.
 5. A process for preparing linear, alternatingα-olefin-CO copolymers as claimed in claim 1, which comprises carryingout the copolymerization of carbon monoxide a) with the olefinicmonomers b) and, if desired, c) in a virtually alcohol-free orwater-free polymerization medium in the presence of a catalyst whoseactive composition is formed fromA') a metal complex of the formula (II)##STR14## where the substituents and indices have the followingmeanings: M is a metal from group VIIIB of the Periodic Table of theElementsE¹, E² are each an element from group VA of the Periodic Tableof the Elements, Z is a bridging structural unit comprising one, two,three or four substructural units of elements of groups IVA, VA and VIAof the Periodic Table of the Elements, R¹ to R⁴ are substituentsselected from the group consisting of C₁ -C₂₀ -organic and C₃ -C₃₀-organosilicon radicals, where the radicals may contain one or moreelements of groups IVA, VA, VIA and VIIA of the Periodic Table of theElements, L¹, L² are formally uncharged Lewis base ligands, X aremonovalent or divalent anions, m, n are 1 or 2, where m×n=2, and B') isan activator component which contains a hydroxyl group in the moleculeand is used, based on M in (II), in an amount of from 0 to 1500 molarequivalents.
 6. A process for preparing linear, alternating α-olefin-COcopolymers as claimed in claim 1, wherein the copolymerization incarried out in the presence of a catalyst whose active composition isformed fromi) a salt of a metal M of group VIIIB of the Periodic Tableof the Elements, ii) one or more compounds selected from the groupconsisting of protic acids and Lewis acids, iii) a chelating compound ofthe formula (III)

    R.sup.1 R.sup.2 E.sup.1 --Z--E.sup.2 R.sup.3 R.sup.4       (III),

where the substituents and indices have the following meanings: E¹, E²are each an element from group VA of the Periodic Table of the Elements,Z is a bridging structural unit comprising one, two, three or foursubstructural units of elements of groups IVA, VA and VIA of thePeriodic Table of the Elements, R¹ to R⁴ are substituents selected fromthe group consisting of C₁ -C₂₀ -organic and C₃ -C₃₀ -organosiliconradicals, where the radicals may contain one or more elements fromgroups IVA, VA, VIA and VIIA of the Periodic Table of the Elements, iv)an activator component B') which contains a hydroxyl group in themolecule and is used, based on M in (II), in an amount of from 0 to 1500molar equivalents.
 7. A process for producing fibers, films, moldings,ion-selective membranes and coatings, in which linear, alternatingα-olefin-CO copolymers as claimed in claim
 1. 8. A fiber, film, moldingor coating comprising a linear, alternating α-olefin-CO copolymer asclaimed in claim
 1. 9. An ion-selective membrane comprising anα-olefin-CO copolymer as claimed in claim
 1. 10. An ion-selectiveelectrode or a chemically modified field effect transistor comprising assignificant constituent an ion-selective membrane as claimed in claim 9.